(1) Field of the Invention
This invention relates generally to automated chromatographic column operations, including column equilibration, column loading, column washing, and column elution. More particularly, the invention resides in a system in which a chromatographic column is moved in an automatic programmed sequence from one fluid source or discharge point to another. The invention is especially directed at the adaptation of an automatic pipetting system to an automatic chromatographic system.
(2) Description of the Prior Art
Many laboratory procedures rely upon column chromatographic methods. These procedures include the purification of DNA and oligonucleotides, preparation of poly A RNA and high molecular weight genomic DNA, and the recently developed column-based solid phase method of performing Maxam-Gilbert sequencing reactions. See "Use of Reverse-Phase Chromatography in the Maxam-Gilbert Method of DNA Sequencing: A Step Toward Automation," Jagadeeswaran, P. and Kaul, R. K., Gene Analysis Techniques, 3:79-85 (1986). In a multi-step procedure such as Maxam-Gilbert sequencing reactions, using commercially available columns and running them is a labor intensive process.
Robotic pipetting machines are well known in the art. For instance, the Biomek.RTM. 1000 Automated Laboratory Workstation (Beckman; 2500 Harbor Boulevard, Fullerton, Calif.) comprises a robotic arm which can hold a pipette tool and is capable of vertical and horizontal (forward and backward) movement. The Biomek.RTM. 1000 includes a platform which carries pipette tools, and separate storage ports which are holding places for pipette tips and fluids. The Biomek.RTM. 1000 can be programmed to move a pipette tool and connect to a pipette tip in such a manner as to enable the tool to intake and discharge liquid through the pipette tip. Typically, the Biomek.RTM. 1000 is programmed to move a pipette tool to a pipette storage location, connect the tool to a pipette tip, move to an instructed port which holds a liquid, pick up an instructed amount of liquid, and deliver this liquid to another location.